8.8 Front wheels ............................................................................................................................ 66
8.8.1 Repairing a flat tire in the front ...................................................................................... 66
8.8.2 Replacing the steering head bearings on the steering wheels ..................................... 66
8.8.3 Changing a front wheel (normal front wheel) ................................................................ 69
8.8.4 Changing a front wheel (suspended front wheel) ......................................................... 71
8.9 Drive wheels ............................................................................................................................. 72
8.9.1 Replacing the drive wheel ............................................................................................. 72
8.9.2 Replacing a tyre or inner tube ....................................................................................... 73
8.9.2.1 Replacing puncture-protected tyres ......................................................................... 73
8.9.2.2 Replacing puncture-proof tyres ................................................................................ 75
8.9.3 Replacing the drive wheel hub ...................................................................................... 76
8.10 Drive unit .................................................................................................................................. 77
8.10.1 Replacing the motor/transmission unit .......................................................................... 77
8.10.2 Replacing or rotating the motor / gearbox unit sealing ring .......................................... 79
8.10.3 Replacing the motor / gearbox coupling ....................................................................... 80
8.10.4 Replacing the carbon brushes ...................................................................................... 82
8.10.5 Fitting the clutch rotary knob (SSD motor) .................................................................... 84
8.11 Replacing the rubber shock absorbers ................................................................................. 85
8.12 Replacing the tube frame ........................................................................................................ 87
8.13 Replacing the double bearing of the Dual Swing Technology (D.S.T.) .............................. 89
8.14 Replacing the battery boxes ................................................................................................... 91
8.15 Seat system .............................................................................................................................. 92
8.15.1 Replacing the tilt actuator ............................................................................................. 92
8.15.2 Replacing the tilt module ............................................................................................... 94
8.15.3 Replacing the lifter / tilt module ..................................................................................... 96
8.16 Backrest unit .......................................................................................................................... 100
8.16.1 Replacing the standard backrest ................................................................................ 100
8.16.2 Replacing a standard backrest with quick release ...................................................... 102
8.16.3 Replacing a Flex2 backrest ........................................................................................ 103
8.16.4 Adjusting backrest former ........................................................................................... 104
8.17 Seat system Modulite ............................................................................................................ 105
8.17.1 Replacing the tilt actuator ........................................................................................... 105
8.17.2 Replacing the lifter actuator ........................................................................................ 106
8.17.3 Replacing the lifter / seat angle adjustment module ................................................... 107
8.17.4 Replacing the backrest actuator ................................................................................. 110
8.18 Backrest Modulite .................................................................................................................. 111
8.18.1 Replacing the standard backrest ................................................................................ 111
8.18.2 Replacing the backrest mounting bracket .................................................................. 112
8.18.3 Replacing the backrest mounting bracket for SB 53 .................................................. 113